Syphilis: Dermatologists should watch for telltale signs of resurgent disease state

March 5, 2016

Kenneth Katz, MD, told audience members that the incidence of syphilis is on the rise and warned that it can mimic other dermatologic conditions.

Syphilis is the comeback kid re-emerging throughout the United States, and dermatologists are in a prime position to detect the disease, which can include debilitating neurosyphilis and ocular syphilis even during early stages. However, dermatologists risk missing the diagnosis if they aren’t thinking about or considering syphilis as a possibility, warned Kenneth Katz, MD, course director for Friday’s session “Sex, Sores, Science, and Surveillance: Syphilis in the 21st Century.”

“Syphilis is often thought of as a disease we got rid of in the 20th century, but we are going back to the future with this illness,” said Dr. Katz, dermatologist for Kaiser Permanente of Northern California, Pleasanton. “In the past 15 years, the incidence of syphilis has more than tripled from approximately 6,000 new cases of primary and secondary syphilis each year to nearly 20,000 a year today.”

Syphilis is known as the great mimicker because it looks like some other dermatologic conditions. The disease should be in the differentials of diagnosis with the appearance of rashes on the trunk, spots on the hands, and sores in the genital or other areas. Congenital syphilis also should be in the differential diagnosis for newborns with rashes on the body and other telltale signs, such as rhinitis with mucous.

Dr. Katz emphasizes the importance for clinicians to obtain a patient’s sexual history to determine his or her level of risk. Currently, the epidemic is especially widespread among men who have sex with men, particularly those living with HIV.

Because neurosyphilis and ocular syphilis can occur during any stage of syphilis, it’s critical to take a neurologic and ophthalmic history and, if indicated, conduct a neurologic and ophthalmic evaluation. To help prevent congenital syphilis, the CDC recommends screening pregnant women at their first prenatal visit and again at 28 weeks if they live in geographic areas with a high prevalence of the illness among newborns.

Every state requires that clinicians and laboratories report suspicious or confirmed cases of syphilis to public health authorities. Public health workers in many cases then reach out to syphilis patients to inquire about recent sex partners so they can be contacted for testing and treatment.

Dr. Katz recommends that clinicians inform patients about the public-health reporting requirement and about the likely outreach from public health workers, emphasizing how cooperating with public-health workers can help stop the chain of syphilis transmission and contribute to combatting the epidemic.

The algorithm for serologic diagnosis of syphilis often starts with treponemal tests such as enzyme or chemiluminescent immunoassays. This newer “reverse-sequence” approach to serologic diagnosis of syphilis is often more cost-effective for laboratories.

The CDC-recommended treatment for adults with primary, secondary, or early latent syphilis without neurosyphilis is benzathine penicillin G in a single 2.4 million unit dose. Treatment is much more complicated for neurosyphilis, requiring intravenous infusion
of aqueous crystalline penicillin G for 10 to
14 days.

“Because of the current syphilis epidemic, we really need to rekindle our ability to diagnose and manage syphilis and become expert syphilologists once again,” Dr. Katz said.